Silver Snail Medic

Silver is the result of selection from introduced land races, derivatives of Sava, selected and bred by Q.D.P.I. Silver performs best in areas with arable neutral-alkaline soil types requiring early to mid maturity. Silver has shown very good adaptation to a range of soil types including the heavy textured soils through to sandy loams soils above pH 7. Flowering in Silver occurs approximately 77 days after germination, approximately four days after Sava. Silver has hard seed levels, slightly higher than Sava. Silver is relatively upright in its growth habit, which allows the variety to compete very effectively for light. The pods of snail medics are more vulnerable than those of barrel medics because of size, as sheep will graze pods of snail medics and can severely reduce seed reserves in the soil. Silver has shown distinct yield advantages over Sava, particularly in heavy textured soil.

Pasture type and use

Generally winter growing annual ley legume in dryland cereal growing regions of southern and subtropical Australia, where it is grazed by livestock or cut for hay. It is suited for hay production because of its upright growth. It may be used as a legume component in permanent grass/legume pastures in the cooler subtropics.

Where it grows

Rainfall: Requires an annual rainfall of 300 - 700 mm.Soils: Suited to neutral to alkaline medium loams to heavy clay soils; regenerates best on self-mulching soils. Temperature: A winter/spring growing annual that can withstand low temperatures, although production is limited by frosts. More productive when sown in early autumn.

Establishment

Companion species: Often grown with winter cereals such as oats for grass/legume hay production; sown with other medics including barrel medic in the subtropics and gama medic in southern Australia. It regenerates later than barrel, strand and burr medics.Sowing/planting rates as single species: 15 - 18 kg/ha. * ensure seed is Goldstrike treated. Sowing/planting rates in mixtures: Sow at a rate depending on the proportion in the mix, but generally 3 - 4 kg/ha. * ensure seed is Goldstrike treated. Sowing time: Early autumn to early winter.Inoculation: GoldstrikeTreated. The use of Goldstrike XLR8 seed treatment is recommended to reduce damage from insects at seedling stages. Fertiliser: Where soils are low in nutrients, particularly phosphorus (P) and/or sulphur (S), it would be beneficial to apply 10 - 15 kg P and 10 kg S/ha annually, and copper (Cu), zinc (Zn) and molybdenum (Mo) if they are deficient. Soil tests will determine the need and appropriate rates. In permanent pasture, fertilise according to deficiencies identified in soil tests.

Management

Maintenance fertiliser: Snail medic is generally grown in rotation with crops. If the soils are deficient, particularly in P and S, the crops are fertilised accordingly. In a rotation system, there should be sufficient residual fertiliser for good medic production. Soil tests will determine the need and appropriate fertiliser rates.Grazing/cutting: In the establishment year, delay grazing until plants are well established. Graze leniently until flowering then remove stock to maximise seed set. Rotationally graze in following years. Snail medic is susceptible to heavy grazing. Pods may be eaten by sheep grazing the pasture during the summer and on soils that are not self-mulching, this may reduce the seed reserve significantly. Ability to spread: Small amounts of seed are spread in the dung following ingestion by livestock. Seed can also be spread through hay. Weed potential: Low weed potential as snail medic is palatable and readily eaten by livestock, and is limited in its soil adaptation. Being a self regenerating annual with a staggered germination, it can be a weed of cereal and grain legume crops. Major pests: Some tolerance to red legged earth mite, lucerne flea and spotted alfalfa aphid, but susceptible to blue green aphid. Major diseases: Susceptible to root rot, alfalfa mosaic virus, and black stem fungus/phoma. Herbicide susceptibility: Susceptible to residual herbicides from a cropping phase, particularly sulfonylurea on alkaline soils.

Animal production

Palatability: Readily eaten by livestock as green feed or hay.Production potential: Live weight gain of 1 kg/day with cattle or 300 g/day with lambs can be expected. Livestock disorders/toxicity: Occasionally red gut in sheep; can cause bloat in cattle, though with a lower probability than other medics.